Download Depressants (Downer`s)

Depressants (Downer’s)
ie. Tranquilizers, sedatives and hypnotics calm and relax the CNS,
slow down activity of brain & other organs, reduce rate of
breathing and dull emotional responses
Tranquilizers – alcohol, valium, Librium
- reduce nervous tension and anxiety but do not produce
normal sleep
- benzodiazepine tranquilizers more safe than barbiturates
(depressants)
Sedatives – soothing of distress, without producing sleep in
normal doses
-more strong than tranquilizers
Hypnotics – chloral hydrate
- produce sleep
- Phenobarbital can behave as a sedative or a hypnotic
depending on the dose
In order of increasing dose:
1.
2.
3.
4.
5.
6.
7.
8.
normal
relief of anxiety
Dis-inhibition
Sedation
Hypnosis
General anaesthesia
coma
DEATH!
ETHANOL!
C2H5-O-H
Hydrogen bonding possible due to hydrogen atom attached to a
highly electronegative oxygen atom. It is also fat soluble b/c it’s
a small organic molecule and can penetrate cell tissue membranes
and easily absorbed by gastrointestinal tract.
Social Effects – abuse leading to sickness and death
-high cost to society, including crime, pain and suffering of
victims and motor traffic accidents
Physiological effects- abuse involves a pattern of drinking
associated with failure to fulfill major obligations, drinking while
driving, operating machinery, physically harming someone
- Alcoholism characterized by an inability to control intake,
a compulsion to drink, and inability to stop
- Physical dependence involves withdrawal symptoms and
tolerance involves the need for increasing amounts of the
drug to feel the same effects
- A disease which involves a psychological and physical
addiction to alcohol as well as genetic factors
Short-term Effects- as a CNS depressant, it reduces tension,
anxiety and inhibitions
- impairment directly related to concentration of alcohol in
the blood
Long-term Effects – cirrhosis (due to scar tissue), cancer of the
liver, coronary heart disease, high blood pressure, strokes,
gastritis, peptic ulcers
-physical dependence, tolerance, depression, anxiety, poor eating
habits
-pregnant women can have babies with Fetal Alcohol Syndrome
Blood alcohol Concentration
mg/100 cm3 of blood
10-30
30-90
90-200
200-300
300-400
350-450
>450
Symptoms
Near normal behavior
Euphoria, sociability,
talkativeness, feeling of
relaxation, increased self
confidence, less inhibitions,
impairment of judgment and
control
Small blood vessels dilated,
feeling of warmth, loss of
critical judgment, impairment
of perception, accident more
likely, drowsiness
Violent or aggressive behaviour
possible, increased pain
threshold, slurred speech,
vomiting
Loss of motor function, general
inertia, impaired consciousness
Coma, unconsciousness
Death from respiratory arrest
Interactions with other drugs – enhances the effects of other
drugs sometimes leading to devastating effects
-if inhibit the breakdown of other drugs, can lead to longer
retention times in the body with increase effects
0.08% blood alcohol level = 80 mg/100 cm3 of blood
Since it’s sufficiently volatile, it passes into the lungs and
establishes an equilibrium
C2H5OH (blood)  C2H5OH (vapour)
Therefore, the concentration in the lungs will depend on the
concentration in the blood
Breathalyser test- redox reaction
K2Cr2O7 is the oxidizing agent that is reduced from Cr (IV) to CR
(III)
Any alcohol is oxidized to ethanoic acid CH3COOH
Cr2O72- + 12 H+ + 6 e-  2 Cr3+ + 7 H2O
reduction ½ rxn
C2H5OH + H2O  CH3COOH + 4e- + 4 H+ oxidation ½ rxn
2 Cr2O72- + 3 C2H5OH + 16 H+  3 CH3COOH + 11 H2O
Analysis carried out by gas liquid chromatography and infra-red
spectroscopy
GLC- involves a sample being vapourised and injected onto the
head of the chromatographic column. The sample is transported
through the column by the flow of inert, gaseous mobile phase.
The column itself contains a liquid stationary phase which is
adsorbed onto the surface of an inert solid.
-A non-selective detector responds to all compounds except the
carrier gas, a selective detector responds to a range of
compounds with a common physical or chemical property and a
specific detector responds to a single chemical compound.
Valium (diazepam) is a tranquilizer
Nitrazepam (Modgadon) is a hypnotic drug used to control
seizures and spasms
Prozac (Fluoxetine Hydrocholoride is an anti depressant to treat
mental depression by increasing serotonin (a neurotransmitter)
Stimulants
Uppers! Are chemical that stimulate the bran and the CNS by
increasing mental alertness ie. Amphetamines, nicotine and
caffeine
Phenylethylamine
Adrenaline
Amphetamine
Speed
Amphetamines mimic the effects of the hormone adrenaline and
are known as sympathomimetic drugs.
-they constrict the arteries, increase sweat production and act
on CNS
-used to treat depression, narcolepsy, asthma
-increase heart rate, blood pressure, respiration, wakefulness
-elevation of mood followed by fatigue, depression, can lead to
blackout or collapse